Unified Model for a Nonlinear Pulse Propagation in Composites and Optimization of THz Generation

TL;DR

This paper presents a comprehensive numerical model and software for simulating nonlinear pulse propagation in composites, enabling optimization of THz generation with improved efficiency and understanding of underlying nonlinear effects.

Contribution

A unified model and software package for simulating complex nonlinear light propagation in composites, applied to optimize THz generation efficiency.

Findings

Achieved 3% THz generation efficiency in ZnO/fused silica composites.

Identified key nonlinear effects influencing frequency conversion.

Optimal THz generation conditions differ from intuitive expectations.

Abstract

We describe a unified numerical model which allows fast and accurate simulation of nonlinear light propagation in nanoparticle composites, including various effects such as group velocity dispersion, second- and third-order nonlinearity, quasi-free-carrier formation and plasma contribution, exciton dynamics, scattering and so on. The developed software package SOLPIC is made available for the community. Using this model, we analyze and optimize efficient generation of THz radiation by two-color pulses in ZnO/fused silica composite, predicting an efficiency of 3\%. We compare the role of various nonlinear effects contributing to the frequency conversion, and show that optimum conditions of THz generation differ from those expected intuitively.